While the Curiosity rover has just begun to investigate its new home, NASA is already developing its follow-up. Yesterday at the American Geophysical Union meeting in San Francisco, the space agency filled in more details on its plans to go back to the surface of Mars. John Grusnfeld, NASA's associate administrator for science and a former astronaut, said the U.S. would send a new rover in 2020, at a cost of about $1.5 billion.

1. More Love For Mars

The Mars 2020 rover will close a busy decade on the Red Planet. Curiosity is now exploring the region near Mount Sharp and testing the chemistry of the Martian soil. Next year, NASA aims to send the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter, which will study the planet's upper atmosphere. The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission, a stationary lander that will dig down to study the Martian interior, is slated for 2016. Europe plans to send 2016 and 2018 missions to Mars, with NASA providing some equipment. Finally, this new, as-yet-unnamed rover will blast off in 2020.

2. Spare Parts

Despite the smashing success of Curiosity so far, NASA planetary science isn't exactly flush with cash. One cost-saving tactic for the 2020 rover: building it on the bones of Curiosity, and reusing some of the leftover parts and backup systems. (Grunsfeld calls them "flight-qualified spares.") "Now that we've publicly announced this, JPL can start going through their spares closet," he says.

One early nominee: The 3D camera that filmmaker and uber-geek James Cameron built for Curiosity, which was left behind. Cameron was at the AGU meeting, and reportedly was ready to lobby for the camera as soon as he learned NASA's plan. "I was a big fan of the 3D and the zoom lens," Grunsfeld says. "We didn't have the opportunity for Curiosity. But I'm more than happy to engage in the spirited discussion for this next rover."

That discussion will come. Now that it's announced the mission, NASA will take proposals from scientists for the payload.

3. Prelude to Humans

All these Mars missions over the next decade should reveal new insights about the planet's history and makeup. And, NASA insists, they are also a lead-up to President Obama's ultimate goal of putting humans on the Red Planet in the 2030s. "A mission to Mars is hugely risky, no matter what," Grunsfeld says. "[But] since before the days of Von Braun, humans [have wanted] to go to Mars."

How can robotic rovers help? Curiosity is already beginning to study the radiation on the surface to determine just how dangerous it would be for any humanoid visitor. Grunsfeld says the 2020 rover would use a heat shield the size of Orion's (the Multi-Purpose Crew Vehicle) to land on Mars. That should teach NASA how to scale up to bigger landers. And, at some point, NASA hopes to execute a sample return mission that would demonstrate the possibility of bringing a spacecraft home from Mars.

4. Incensed Icy Mooners

The Martian love-fest has some scientists saying, "Hey! What about the rest of the solar system?"

When pressed about the dissatisfaction of the "icy moon people," Grunsfeld replied that going to the outer solar system is really difficult, but that he expected NASA to move forward with missions to places like Jupiter's moon Europa, and that the scientists behind endeavors like Titan Mare would resubmit their proposals. However, planetary science blogger Emily Lakdawalla tweeted, "Grunsfeld's wrong about Titan Mare Explorer; it can't be reproposed, because of orbital dynamics. This round was TiME's only chance."